@CarolinaGX It's great that you have the tools and jacks to measure articulation. My floor jack barely lets me change the tire when lifting from the axle, so I can't measure my articulation in my driveway unless I get creative. I don't have ramps either.
My rear lift is somewhat similar to yours. I have the 4R Gen2 end links (Proforged ones) like yours and are about 1" longer than the GX470 stock oem end links. I'm also using the MetalTech coil conversion kit stage 2 with the Toyota isolators. And I'm awaiting the backordered ReszFab offset, extended by 1/8" to 3/16", and non-adjustable rear lower links. I do have the Icon extended rear shocks 56550 (17/27.5) and the variable rate Dobinson C59-675V coils, so I'm eager to figure out how to measure articulation once my setup is complete, but it's good to know that the sway bars are not limiting your articulation and gives me hope to articulate more with my extended rear shocks and coils.
Getting back to the OP...how does all this tie back to the original question? Well, you have the shorter GX470 stock oem rear sway bar end links and you also have the straight factory oem rear lower links. These two items might limit your flexibility/articulation a little more than CarolinaGX. That would be my guess, but not sure.
Also,
@dsm4ever compare the OME rear coils to the Dobinson ones:
* OME 895 15.35" free length, 260 lbs/in spring rate
* OME 2895e 14.76" free length, 260 lbs/in spring rate
Compare that to the Dobinson rear coils:
* Dob C59-675V 18.5" free length (although my used ones were 19"), 16mm wire, 157-230 lbs/in variable rate.
* Dob C59-325 16.54" free length, 17mm wire, 220 lbs/in spring rate
And notice the higher spring rate on the OME's. That's why they like to have some weight on them.
Anyways, it seems to me that you might not get the full 2.75" rear lift that you were predicting...maybe at 2" and your stock oem rear lower links and stock oem rear sway bar end links might contribute to limiting the articulation.
But maybe someone with a similar setup that you are describing can chime in.